During operation, internal combustion engines generate various combustion by-products that are emitted from the engine in an exhaust gas stream. As such, an exhaust gas treatment system is included in an exhaust system of the engine in order to reduce regulated emissions, for example. In some examples, the exhaust gas treatment system may include a plurality of legs, each including one or more exhaust gas treatment devices, through which the exhaust gas stream is distributed. In such an example, it may be desirable to distribute portions of the exhaust gas stream to each of the plurality of legs as desired (e.g., equal distribution of flow). Further, structural requirements may limit the space in which the exhaust gas stream is distributed, thereby increasing a likelihood of an unequal distribution of the exhaust gas stream across the plurality of legs.